Introducing a new processor architecture takes a colossal effort. AMD's modular Bulldozer design ran into its share of resistance at launch. Can a handful of software updates turn the company's flagship FX-8150 into the powerhouse AMD promised?

The fact that AMD’s Bulldozer architecture failed to set the PC world on fire is no secret (AMD Bulldozer Review: FX-8150 Gets Tested), its eight integer cores sharing the resources of a four-module design. AMD credits its effort with lower power consumption compared to a full eight-core design, and even showed off plenty of benchmarks at its press events to demonstrate that the performance of its configuration was truly competitive in the right tests. At the end of the day, though, we were left unimpressed with Bulldozer's position relative to the competition, even though we gave it a fighting chance in our System Builder Marathon, Dec. 2011: $1200 Enthusiast PC.

In our launch story, we made it very clear that Windows 7 is not optimized for the module-based layout that Bulldozer employs. Chris talked to representatives at Microsoft who were able to confirm the operating system's behavior, and he ran the developer build of Windows 8 to confirm the next-gen OS would handle the FX family differently. From that review:

"According to Arun Kishan, software design engineer at Microsoft, each module is currently detected as two cores that are scheduled equally. So, in a dual-threaded application, you might see one active module and three idle modules—great for optimizing power, but theoretically less ideal from a performance standpoint. This also plays havoc with AMD’s claim that, when only one thread is active, it has full access to shared resources. Adding just one additional thread could tie up those shared resources, even as multiple other modules sit idle.

Microsoft is looking to change that behavior moving forward, though. Arun says that the dual-core modules have performance characteristics more similar to SMT than physical cores, so the company is looking to detect and treat them the same as Hyper-Threading in the future. The implications there would be significant. Performance would unquestionably improve, while AMD’s efforts to spin down idle modules would be made less effective."

This explanation does make sense for certain workloads. Two threads running on two separate modules have access to two front ends (and two FPUs), while two cores running on a single module must share both the front-end and FPU. A smarter OS might know the most effective way of distributing the load, which AMD stated would be a feature of Windows 8. Fortunately, MS released a hotfix to address some of what was purportedly going wrong in Windows 7.

There remained, however, a performance penalty in the form of latency if the task that would have been scheduled to an already-active module is instead sent to a “parked” core. Microsoft introduced a second hotfix to address that issue. Put together, these two patches should help overcome the Bulldozer architecture's performance issues in lightly-threaded applications.

We followed up with Microsoft yet again for comment, and heard back that that the core scheduler indeed now recognizes AMD's modules as SMT sets. However, the Windows 7 patches still should not be taken as an indication of how FX will behave under Windows 8. Apparently, there will be additional scheduler improvements that relate to how SMT is treated.

Although Microsoft helped AMD address how the Bulldozer architecture is addressed in less demanding workloads, there is still an issue we've seen on the FX-8150, where the 3.6 GHz part throttles down to 3.3 GHz under a full load. That’s probably considered a power-saving feature in densely-packed 2U servers. However, desktop users have the option to disable this strange step backward through the HPC Mode options exposed through recent firmware updates.

Our goal today is to find out how the latest ecosystem improvements help AMD's early-adopting customers. We're going to test with the benchmarks we normally run, too, and not the hand-picked titles AMD is using to illustrate the gains enabled by Microsoft's new patches.

when it come to processor reviews, the reviews always seem biased towards games...

the point im trying to make is that i have athlon64 3200+ (venice) 754, agp, 3gig ram, x1950pro 512, (soon to be hd4670, as i want to play swords of the stars 2).. its single core built in 2004 runs windows 7.. it plays games at pretty decent fps and i have little or no reason to upgrade it...

if i did, it would require a rebuild, and i would probabily base it on a athlon//phenom 2 dual/tri core setup.. i think processors reached a threshold a few years back in that it makes little difference on having the latest multicore processors.. chips like bulldozer show their strength in render farm setups and other demanding application enviroments.. not games!!

@jrtolson a majority of custom and high end systems are built/brought by gamers.User average user isn't going to go out and spend $/£/€250 on a the processor alone just for browsing the web and emails.The other market is power users which is what the productivity and media converting benchmarks are for.

If your happy with your system thats fine, but most PC gamers want to be able to play modern games at decent resolutions with the eye candy turned on.As for none gaming applications you'd be surpized at the the difference a newer processor would make. Lets not even talk about trying to encode/transcode media on your system...

@joedastudd for the most part u are right, but owning a athlon/phenom or even an older intel core 2 duo with a decent gfx card will allow most games at max or near max settings this is because the games are originally developed for consoles so any pc with similar or new setup than the 360/ps3 should be able to run games no problem.. u are right on the media thing tho, however the point i was making is that the review should concentrate on that more than fps in games.. i as a potential buyer would want to know for e.g how much does having an 8 core fx benefit me in rendering an animation in lightwave 3d (for e.g) against a similar priced 4 core intel product?

the only way i can describe wot i mean, is like reviewing a new Supercomputer capable of trillions of operations per nano second (exagerating lol), then slating it because it runs skyrim 2 fps slower than a intel i7?

for wot i understand the bulldozer has extended pipelines so that when using optimised threaded workloads ot runs faster, however bacause of the extended pipeline un optimised code will run per clock slower..

so to me this means optimised batch processing should fly on these chips, so amd must have targeted the FX line at pro power user market and not gamers? imo

i always said FX was not a gaming part, but rather a productivity 1. if you want to play games then amd fx just doesnt cut it at the price. but if you need highly threaded programs like photoshop then its worthy.but the forum is gonna be over run buy amd fanboys who ignore good advice and just buy phenom 2 for gaming, asking why there systems dont perform... even with a different o.s. its unlikely the fx will ever be a true gaming grade part. unless every game coming out needs 8 cores...